About: consistent hashing

Transcript

1. ӋԍӏӑӞԍӠӧӜӏӾʂҍ҅ѥ҈ ӬӆӏӮװɒױґҭѭѷҵ
2. ѵѵ҉ѥѧӧӜӏԍӇҊґ
3. Ό਺ҐӄـҴΌ਺ҐӦـӡҍðҬƾ҈ҁѥ
 Ҋѥѧī୊
4. ׏ֿ ׏׀ ׏ׁ ׏ׅ ׏׆ ׏ׇ ׏ֿ־ ׏ֿ ׏׀ ׏ׁ ׏ׂ ׏׃ ׏ׄ ӄـ Ӧـӡ
5. ׏ֿ ׏׀ ׏ׁ ׏ׅ ׏׆ ׏ׇ ׏ֿ־ ׏ֿ ׏׀ ׏ׁ ׏ׂ ׏׃ ׏ׄ ˅૝ˤҍґѵѧҌ҆҈ҝѹѥ Ӧـӡ
6. ѵҮѮ҉ѯҭҊ
   ؆
   !׌ҐӏӼـӟҺԍӇ
   ؆
   ӄӼӜӏӾҐåࢄشࠓ´҆҈ҭҥ҅
   ؆
   Ҍҍѭѣҭҥ҅ҴҌҵѭͮѥײѺҍåð
   ……ҊѭҠѣѥүѥүҊ¸ê
7. €˕ӏԍӯԃҌȠʂ
   פӺӐӾԅʂץ
8. ׏ֿ ׏׀ ׏ׁ ׏ֿ ׏׀ ׏ׁ %3 = 1 %3 = 2 %3 = 0 ׏ׂ %3 = 1 ӺӐӾԅʂ
   Ӧـӡ਺Ґ৒²ҴҊҭ ׏׃ ׏ׄ %3 = 2 %3 = 0
9. ӺӐӾԅʂ׋
   ؆
   ÅҬѮχѵҫҌѱ҈ͮѷѿѧ
   ؆
   ӏԍӯԃ
   ؆
   ӦـӡҴϟՃѻҭҊѯҍŖő
10. ӺӐӾԅʂ ׏ֿ ׏׀ ׏ׁ ׏ֿ ׏׀ ׏ׁ %3 = 1 %3 = 2 %3 = 0 ׏ׂ %3 = 1 ׏׃ ׏ׄ %3 = 2 %3 = 0
11. ӺӐӾԅʂ ׏ׂ ׏ֿ ׏׀ ׏ׁ ׏ֿ ׏׀ ׏ׁ %3 = 1 %3 = 2 %3 = 0 ׏ׂ %3 = 1 ׏׃ ׏ׄ %3 = 2 %3 = 0
12. ׏ֿ ׏׀ ׏ׁ ׏ֿ ׏׀ ׏ׁ %4 = 1 %4 = 2 %4 = 3 ׏ׂ %4 = 0 ӺӐӾԅʂ ׏ׂ ׏׃ ׏ׄ %4 = 1 %4 = 2 ӦـӡҴϟՃѻҭҊѯҍŖő׎׎׎ ׏׀¦߱ѻқ҈҉ȳѯȈѩѮˠੜ
13. פӺӐӾԅʂץґ
    ࣮ΆѮ؆୯҂ѮӦـӡҐϟՃ؏࡟আѮŖő
14. ӋԍӏӑӞԍӠӧӜӏӾʂ • @_LE
    @YJFY
    F[
    @Q׌
    ،TSZLZ[FS[
    @ZKLSJ
    @SE
    @SETR
    YFFZ׋LZ[YLC\[FE
    @DKLSJ
    YT[TDTQZ
    ITY
    FQLF_LSJ
    T[
    WT[Z
    TS
    [KF
    "TYQE
    "LEF
    "FC،
    ׮ׇׇֿׅׯ
    • ࣮ΆҊѹ҈ґFRD@DKFEҐҁңҐF[@R@ѮȵĚ
 K[[WZ׋זזJL[K\CאDTRזזPF[@R@
    • SJLSa׍W@DKF
    Y@IILDFY_FYҤ࠾ˉ
15. ӋԍӏӑӞԍӠӧӜӏӾʂ׋
    ؆
    ӧӜӏӾВ਺ґ€ɠҍåƖѻҭґѼ
    ؆
    ӧӜӏӾВ਺ҴԂԍӇ…ҍѹ҈࣮Ά
    
16. ׏ֿ ׏׀ ׏ׁ ӋԍӏӑӞԍӠӧӜӏӾʂ
 Ӧـӡ׍ӄـҐѿҮҀҮҴęѺӧӜӏӾ̌БҍࣹӨ @ZK׮ @ZK׮ @ZK׮ ׯ ׯ ׯ ӧӜӏӾ̌Б
17. ׏ֿ ׏׀ ׏ׁ @ZK׮ @ZK׮ @ZK׮ ׯ ׯ ׯ ӧӜӏӾ̌Б ׏ֿ ׏׀ ׏ׁ ׏ׂ ׏׃ ׏ׄ @ZK׮ @ZK׮ @ZK׮ @ZK׮ @ZK׮ @ZK׮ ׯ ׯ ׯ ׯ ׯ ׯ ӋԍӏӑӞԍӠӧӜӏӾʂ
 Ӧـӡ׍ӄـҐѿҮҀҮҴęѺӧӜӏӾ̌БҍࣹӨ
18. ׏ֿ @ZK׮ ׯ ׏ֿ ׏׀ ׏ׁ @ZK׮ @ZK׮ @ZK׮ ׯ ׯ ׯ ۙѥÃҴબ୒ ׏ֿ ׏׀ ׏ׁ ׏ׂ ׏׃ ׏ׄ @ZK׮ @ZK׮ @ZK׮ @ZK׮ @ZK׮ @ZK׮ ׯ ׯ ׯ ׯ ׯ ׯ 
    ֿ˕…ҐÃҴҊҭ ؼ ӧӜӏӾ̌Б ӋԍӏӑӞԍӠӧӜӏӾʂ
 Ӧـӡ׍ӄـҐѿҮҀҮҴęѺӧӜӏӾ̌БҍࣹӨ
19. ӋԍӏӑӞԍӠӧӜӏӾʂ׋
    ؆
    ӧӜӏӾВ਺ґ€ɠҍåƖѻҭґѼ
 ؕҌҐ҉ÅҫҌѥ
    ؆
    ȳѯȈҰҭҐґӧӜӏӾ̌БҐ€϶҂ѳҐґѼ
 ؕҌҐ҉ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ
20. ׏ֿ ׏׀ ׏ׁ ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ @ZK׮ @ZK׮ @ZK׮ ׯ ׯ ׯ ӧӜӏӾ̌Б ׏ֿ ׏׀ ׏ׁ ׏ׂ ׏׃ ׏ׄ @ZK׮ @ZK׮ @ZK׮ @ZK׮ @ZK׮ @ZK׮ ׯ ׯ ׯ ׯ ׯ ׯ
21. ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ ӧӜӏӾ̌Б ׏ֿ ׏׀ ׏ׁ ׏ׂ ׏׃ ׏ׄ @ZK׮ @ZK׮ @ZK׮ @ZK׮ @ZK׮ @ZK׮ ׯ ׯ ׯ ׯ ׯ ׯ ׏ֿ ׏׀ ׏ׁ @ZK׮ @ZK׮ @ZK׮ ׯ ׯ ׯ ׏ׂ @ZK׮ ׯ ׏ׂҴϟՃ
22. ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ ӧӜӏӾ̌Б ׏ֿ ׏׀ ׏ׁ ׏ׂ ׏׃ ׏ׄ @ZK׮ @ZK׮ @ZK׮ @ZK׮ @ZK׮ @ZK׮ ׯ ׯ ׯ ׯ ׯ ׯ ׏ֿ ׏׀ ׏ׁ @ZK׮ @ZK׮ @ZK׮ ׯ ׯ ׯ ۙѥÃҴબ୒ ׏ׂ @ZK׮ ׯ ȳѯȈҰ҆ҁҐґ׏ׄ҂ѳ׎
23. ӋԍӏӑӞԍӠӧӜӏӾʂ׋
    ؆
    ÅҫҌѥ
    ؆
    ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ
    
    
24. ӧӜӏӾ̌Б ׏ֿ @ZK׮ ׯ ˅૝ˤҍґ ؟ֿذ׀׋
25. ˅૝ˤҍґ ӧӜӏӾ̌Б ׏ֿ ׏׀ @ZK׮ @ZK׮ ׯ ׯ ׏׀ҴϟՃѻҭҊ ؟ֿذ׀׋
    ׃־أ
26. ӧӜӏӾ̌Б ׏ֿ ׏׀ @ZK׮ @ZK׮ ׯ ׯ ׏ׁ @ZK׮ ׯ ˅૝ˤҍґ ؟׀ذׁ׋
    ׀׃أ ׏ׁҴϟՃѻҭҊ
27. ӧӜӏӾ̌Б ׏ֿ ׏׀ @ZK׮ @ZK׮ ׯ ׯ ׏ׁ @ZK׮ ׯ ׏ׂ @ZK׮ ׯ ˅૝ˤҍґ ؟ׁذׂ׋
    ׀׃أ ׏ׂҴϟՃѻҭҊ
28. ӋԍӏӑӞԍӠӧӜӏӾʂ׋
    ؆
    ÅҫҌѥ
    ؆
    ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ
    
    
29. ӋԍӏӑӞԍӠӧӜӏӾʂҐ࣮Ά
 ׮F[@R@ҐńĘׯ
30. # ϋογϡؔ਺͸32bit unsigned intͷϋογϡ஋Λฦ͢
 # CRC32, MD5ͷ্Ґ32bitͳͲͰ࣮૷
 func hash(key string) uint32 { ... } # ϊʔυͷϋογϡ஋Λܭࢉ for _, node := range nodes { # ͻͱͭͷϊʔυຖʹ160ݸͷϋογϡΛܭࢉ for i := 0; i < 160; i++ { k := fmt.Sprintf(“%s-%d”, node, i)
 
 # ϊʔυ໊ͱϋογϡ஋ͷϖΞΛ௥Ճ continuum.add(node, hash(k)) } } # ϋογϡ஋Ͱιʔτ͓ͯ͘͠ sort.Sort(continuum) ֿא
    ӦـӡӶӜӯҐܭࢉ
31. ֿא
    ӦـӡӶӜӯҐܭࢉ ӧӜӏӾ̌Б ׏ֿ @ZK׮ ׯ ֿ҅ҐӦـӡҍରѹ
 Ό਺ҐӧӜӏӾҴܭࢉ
 ذӧӜӏӾܭࢉҍҩҭÅҬҴЕɦ
    ؕ׮׀־־¿ѱҫѥ҉ůŲׯ
32. # ϋογϡ஋Ͱιʔτ͓͚ͯ͠͹ೋ෼୳ࡧͰ୳ࡧͰ͖Δ
 func search(key string) string { v := hash(key) i, j := 0, n for i < j { h := i + (j-i)/2 if (continuum.values[i] > v) { i = h + 1 } else { j = h } } return continuum.nodes[i] } ׀א
    ӧӜӏӾҐ୳ࡧ
33. ׀א
    ӧӜӏӾҐ୳ࡧ ӧӜӏӾ̌Б _ @ZK׮ ׯ ׏ֿ ׏׀ ׏ׁ @ZK׮ @ZK׮ @ZK׮ ׯ ׯ ׯ ׏ׂ @ZK׮ ׯ ™å୳ࡧ҉€˕ۙѥӧӜӏӾҴʹŲ
34. ҠҊң
 ׮ӋԍӏӑӞԍӠӧӜӏӾʂׯ
    ؆
    ÅҫҌѥ
 ؕӧӜӏӾВ਺Ҋѹ҈ґ׃…¯ׁ׀CL[׌
    ׁ׀׌
    !؆ֿ̙
    ؆
    ϟՃѹҁҊѯҐӘӹـӐѮƀҌѥ
 ؆
    ࣮ΆҤӏԍӯԃ